Driver: VMBus: Add Devicetree support

Update the driver to support Devicetree boot as well along with ACPI.
At present the Devicetree parsing only provides the mmio region info
and is not the exact copy of ACPI parsing. This is sufficient to cater
all the current Devicetree usecases for VMBus.

Currently Devicetree is supported only for x86 systems.

Signed-off-by: Saurabh Sengar <ssengar@linux.microsoft.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/1679298460-11855-6-git-send-email-ssengar@linux.microsoft.com


Signed-off-by: Wei Liu <wei.liu@kernel.org>